Reorganized polyfills

src/ArduinoJson/Numbers/FloatParts.hpp

@@ -0,0 +1,89 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "../Configuration.hpp"
+#include "../Polyfills/math.hpp"
+#include "./FloatTraits.hpp"
+
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename TFloat>
+struct FloatParts {
+  uint32_t integral;
+  uint32_t decimal;
+  int16_t exponent;
+  int8_t decimalPlaces;
+
+  FloatParts(TFloat value) {
+    uint32_t maxDecimalPart = sizeof(TFloat) >= 8 ? 1000000000 : 1000000;
+    decimalPlaces = sizeof(TFloat) >= 8 ? 9 : 6;
+
+    exponent = normalize(value);
+
+    integral = uint32_t(value);
+    // reduce number of decimal places by the number of integral places
+    for (uint32_t tmp = integral; tmp >= 10; tmp /= 10) {
+      maxDecimalPart /= 10;
+      decimalPlaces--;
+    }
+
+    TFloat remainder = (value - TFloat(integral)) * TFloat(maxDecimalPart);
+
+    decimal = uint32_t(remainder);
+    remainder = remainder - TFloat(decimal);
+
+    // rounding:
+    // increment by 1 if remainder >= 0.5
+    decimal += uint32_t(remainder * 2);
+    if (decimal >= maxDecimalPart) {
+      decimal = 0;
+      integral++;
+      if (exponent && integral >= 10) {
+        exponent++;
+        integral = 1;
+      }
+    }
+
+    // remove trailing zeros
+    while (decimal % 10 == 0 && decimalPlaces > 0) {
+      decimal /= 10;
+      decimalPlaces--;
+    }
+  }
+
+  static int16_t normalize(TFloat& value) {
+    typedef FloatTraits<TFloat> traits;
+    int16_t powersOf10 = 0;
+
+    int8_t index = sizeof(TFloat) == 8 ? 8 : 5;
+    int bit = 1 << index;
+
+    if (value >= ARDUINOJSON_POSITIVE_EXPONENTIATION_THRESHOLD) {
+      for (; index >= 0; index--) {
+        if (value >= traits::positiveBinaryPowerOfTen(index)) {
+          value *= traits::negativeBinaryPowerOfTen(index);
+          powersOf10 = int16_t(powersOf10 + bit);
+        }
+        bit >>= 1;
+      }
+    }
+
+    if (value > 0 && value <= ARDUINOJSON_NEGATIVE_EXPONENTIATION_THRESHOLD) {
+      for (; index >= 0; index--) {
+        if (value < traits::negativeBinaryPowerOfTenPlusOne(index)) {
+          value *= traits::positiveBinaryPowerOfTen(index);
+          powersOf10 = int16_t(powersOf10 - bit);
+        }
+        bit >>= 1;
+      }
+    }
+
+    return powersOf10;
+  }
+};
+}  // namespace Internals
+}  // namespace ArduinoJson